Biomedical subjects
Publications and source records attributed to V I Dontsov.
Electrochemically activated systems normalized activity of antioxidant enzymes catalase, peroxidase, and superoxide dismutase. The baseline activity of antioxidant enzymes considerably varies in humans and animals. This effect of electrochemically activated systems having negative oxidation-reduction potential was probably related to a training effect of excess electrons.
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The special feature of weak-pulse current effects on immune rosette formation has been investigated in mice. Stimulation of PFC generation could be made in the murine spleen 4 days after immunisation on 5-10-minute weak-pulse current exposure during 1 hour after immunisation. The parameters of signal was: 543 kHz frequency and triangular or quadratic signal form, that is typical for resonance mechanism of different stimuli. The resonance mechanism may be the basis for the influence of low-intensity factors on the body, which allows the low-intensity physical and other exposures to be used in clinical practice.
It has being shown by radiological methods of evaluation of the binding sites with adrenergic, cholinergic and neuropeptide agents that during mice ontogenesis the number of binding sites to these agents is progressively declined. The cAMP accumulation by lymphoid cells after contact with adrenaline is declined also. The regularities shown may reflect processes of the immune change during the age.
The liposomes with incorporated membranes of SC+ lymphocytes, confirmed by ELISA, were obtained. The membranes of this type of lymphocytes but not thymocytes were capable of 3H-cAMP transport into the liposomes. As anti-SC serum inhibited this process, the SC components of lymphocyte membrane may take part in it.
The activation of spleen lymphocytes during tumour growth on the syngeneic mice has been shown. The activated lymphocytes were able to restore the tumour growth after cyclophosphane induction of immunodeficiency. Activated lymphocytes of mice acted the same way with liver regeneration and isoproterenol induction of salivary gland hyperplasia. The inhibitory effect of lymphocytes has been also shown during this process. Both stimulation and inhibition were the function of the ThyI lymphocytes. The regularities shown may reflect important processes of cell proliferation regulation in multicellular organisms.
T-cell phenotype that regulates isoproterenol-induced lymphocyte-dependent hyperplasia of mouse salivary glands and conditions of its activation has been investigated. Stimulated Thy-1 and Ly-1-positive cell populations proliferated in the medium supplemented with both interleukin-1 (IL-1) and interleukin-2 (IL-2). The inhibiting population was Thy-1 and Ly-2-positive, proliferating only in IL-2-containing medium. Both regulatory cell properties and the character of their activation are similar to those of lymphocytes that regulate syngeneic mixed lymphocyte culture. The regularities shown may reflect important processes of cell proliferation regulation in multicellular organisms.
A theoretical analysis of cell proliferation as a selflimiting process designed to maintain the integrity of an entire multicellular organism and based on the principles of a "hypercycle" suggests the need for the existence, starting at a certain level of multicellular organization, of a specialized system in control of tissue proliferation, a system represented by a body of cells capable of both stimulating and inhibiting the proliferation of a variety of cell types. An analysis of experimental data in different fields of the biological science points to certain T-cell populations as probable candidate for the role of cellular regulators of tissue proliferation. Using as an example the induction of murine liver regeneration by the administration of CCL4, the author demonstrates the dynamics of the formation of cells stimulating and inhibiting regeneration, which conforms well to theoretical considerations.
Cyclic guanosine-3'5' monophosphate (cGMP) can mobilize intracellular calcium from the microsomal fraction of B-lymphocytes of the mouse spleen as a result of activation of cGMP-dependent microsomal proteinkinases. The existence of such a mechanism makes B-lymphocytes independent of extracellular calcium in response to agents whose effect on B-lymphocytes is mediated by calcium mechanisms.
Isoproterenol-induced hyperplastic reaction has demonstrated decreased proliferative potency of salivary gland tissue in adult mice. Activation of serotoninergic mechanisms of lymphoid regulation by serotonin administration also decreased salivary gland hyperplastic reaction, predominantly in young mice. Dopamine administration enhanced the reaction in adult mice, it reaching the level observed in young animals. The number of spleen activated low density lymphocytes decreased in the case of serotonin-induced inhibition of hyperplastic reaction to isoproterenol and increased in the case of reaction stimulation. These lymphocytes have been previously shown to regulate salivary gland tissue proliferation in response to isoproterenol.
A study was made of the effects of the neurotransmitters acetylcholine and adrenaline on proliferation of B lymphocytes of mice immunized with ovalbumin. The neurotransmitters were noticed to be capable of changing B cell proliferation on cultivation in vitro. The effect (an increase or reduction of 3H-thymidine incorporation) depended on the time of immunization, antigen dose, and the type of a neurotransmitter. On the whole the pattern of the acetylcholine effect correlated with a natural trend of changes in B lymphocyte proliferation at different times of the immune response. Adrenaline produced a reciprocal effect.
Spontaneous velocity sedimentation of B lymphocytes activated by intraperitoneal injection of ovalbumin into mice was used to obtain cell cycle synchronized cells, evidenced by differences in the incorporation of labeled precursors of protein and nucleic synthesis (14C-methionine and 3H-thymidine). The effects of acetylcholine and adrenaline, cAMP and cGMP on the intensity of 3H-thymidine incorporation into mouse B lymphocytes and on the amount of the cells entering mitosis were examined. It was shown that acetylcholine is capable of stimulating whereas adrenaline of inhibitin B lymphocyte entry into the stage of DNA synthesis and egress of these cells from the stage of DNA synthesis to the stage of mitosis. Adrenaline was found to have a reciprocal action. The acetylcholine effect could be mimetized by exogenous cGMP, that of adrenaline by cAMP. Stimulation of the G1/S transition was mediated by intracellular calcium ions but did not depend on exocellular calcium.
It has been shown that in the course of isoproterenol induction of cell proliferation of rat and mouse salivary glands, there takes place formation of T lymphocytes that stimulate and inhibit proliferation of the gland cells. In the absence of T lymphocytes isoproterenol does not induce cell proliferation. It has been demonstrated in mice that lymphocytes that stimulate cell proliferation of the salivary glands belong to Ly 1+ T lymphocytes whereas those inhibiting proliferation to Ly 2+ T lymphocytes. The former ones are formed and proliferate before commencement of glandular cell proliferation, and the latter ones concurrently with the development of cell proliferation of the salivary glands. The mechanisms described may point to the existence of a special system of T lymphocytes, that is not identical to the immune system, with this special system playing a definite role in the maintenance of the proliferative homeostasis of host tissues.
Study of the effects of acetylcholine, exogenous cGMP and Con A on the mobility of B lymphocytes has demonstrated that an increase in both the content of cGMP and calcium in B lymphocytes stimulates their mobility. The measurement of intracellular content of cGMP in B lymphocytes by radioimmunoassay has shown that this content changes rapidly in response to the action of acetylcholine and that it is dependent but negligibly on extracellular calcium. The dependence of the effects of all three substances on trifluoperazine, a calmodulin v blocker, indicates that stimulation of B lymphocyte mobility is ultimately determined by the calcium mechanisms.
It was shown that B lymphocyte motility activated by anti-immunoglobulin serum may be abrogated in a Na+-deficient medium and in a 10(-5)M trifluoperazine-containing medium but not in a Ca2+-deficient medium. The tetracycline fluorescence test demonstrated Ca2+ efflux from isolated B lymphocyte mitochondria due to Na+ exposure. The radioimmunoassay demonstrated the cGMP level to rise after exposure to anti-immunoglobulin serum. The Na+-dependent Ca2+ efflux from the mitochondria might be the main mechanism in anti-immunoglobulin serum activation of B lymphocytes and in the cGMP level rising.
During sensitization of BALB/c mice to protein antigen, spontaneous and acetylcholine-induced mobility of spleen lymphocytes increased, the maximum being reached on days 1-3 from the sensitization commencement. The acetylcholine-induced mobility of lymphocytes was reduced if the lymphocytes had been preexposed to the antigen. The data obtained attest to the same cellular substrate of antigen and acetylcholine effects.
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